base

Fix bug 5118908 - ImageView.setImageDrawable always requests layout

Make ImageView a bit more conservative about when it requests a
layout. This improves performance for ListViews where apps
asynchronously load images and replace placeholders outside of the
optimized getView path.

Change-Id: I564a4a343ab9c8c2d5baf907b5f573b5ee02c87a